Nine-Point Center
The center 
(or 
) of the Nine-Point Circle. It has Triangle Center Function
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and is the Midpoint of the line between the Circumcenter
and Orthocenter 
. It lies on theEuler Line.See also Euler Line, Nine-Point Circle, Nine-Point Conic
References
Carr, G. S. Formulas and Theorems in Pure Mathematics, 2nd ed. New York: Chelsea, p. 624, 1970. Dixon, R. Mathographics. New York: Dover, pp. 57-58, 1991. Kimberling, C. ``Central Points and Central Lines in the Plane of a Triangle.'' Math. Mag. 67, 163-187, 1994. Kimberling, C. ``Nine-Point Center.''http://cedar.evansville.edu/~ck6/tcenters/class/npcenter.html.
- Ochoa Curve
- Octacontagon
- Octadecagon
- Octagon
- Octagonal Number
- Octagram
- Octahedral Graph
- Octahedral Group
- Octahedral Number
- Octahedron
- Octahedron 5-Compound
- Octahemioctacron
- Octahemioctahedron
- Octakaidecagon
- Octal
- Octant
- Octatetrahedron
- Octic Surface
- Octillion
- Octodecillion
- Octonion
- Odd Function
- Odd Number
- Odd Number Theorem
- Odd Order Theorem